Rust

Create PEM-encoded PKCS#7 Detached Signature

See more Digital Signatures Examples

Demonstrates how to create a PKCS7 PEM-encoded object containing a detached signature. Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

let cert = chilkat::Cert::new();

// Load the cert and private key.
if cert.load_pfx_file("qa_data/pfx/myCertAndKey.p12", "password").is_err() {
    println!("{}", cert.last_error_text());
    return;
}

let crypt = chilkat::Crypt2::new();

if crypt.set_signing_cert(&cert).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

// Use SHA-256
crypt.set_hash_algorithm("sha256");

// Hash the utf-8 byte representation of the string
crypt.set_charset("utf-8");

// Return the result in base64
crypt.set_encoding_mode("base64Mime");

// Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
let text_to_sign = "This is the text to be hashed and signed.".to_string();
let Ok(sig_base64) = crypt.sign_string_enc(&text_to_sign) else {
    println!("{}", crypt.last_error_text());
    return;
};

println!("{}", sig_base64);

// The result:

// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// ...
// ...

// If we want it in PEM format with just LF line-endings:
let sb = chilkat::StringBuilder::new();
// Just LF line endings, not CRLF.
let crlf = false;
let _ = sb.append_line("-----BEGIN PKCS7-----", crlf);
let _ = sb.append(&sig_base64);
let _ = sb.append_line("-----END PKCS7-----", crlf);
let _ = sb.to_lf();

// Save to a file.
let _ = sb.write_file("c:/temp/qa_output/sig.pem", "utf-8", false);

// Examine..
println!("{}", sb.get_as_string().unwrap_or_default());

// Result is:

// -----BEGIN PKCS7-----
// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// DjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3RhbGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUG
// A1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBSb290IENBMB4XDTExMDkyMjExMjIwMloXDTMw
// MDkyMjExMjIwMlowazELMAkGA1UEBhMCSVQxDjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3Rh
// bGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUGA1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBS
// b290IENBMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAp8bEpSmkLO/lGMWwUKNvUTuf
// ClrJwkg4CsIcoBh/kbWHuUA/3R1oHwiD1S0eiKD4j1aPbZkCkpAW1V8IbInX4ay8IMKx4INRimlN
// AJZaby/ARH6jDuSRzVju3PvHHkVH3Se5CAGfpiEd9UEtL0z9KK3giq0itFZljoZUj5NDKd45Rnij
// MCO6zfB9E1fAXdKDa0hMxKufgFpbOr3JpyI/gCczWw63igxdBzcIy2zSekciRDXFzMwujt0q7bd9
// ...
// ...
// -----END PKCS7-----